LXC container gets 2 IP addresses

Question

I want to have a flat configuration where the host and guest all have their own static addresses on the network. For some unknown reason however, the container is assigned 2 addresses, 192.168.0.110 and 192.168.0.201. I'm only interested in having one, 192.168.0.201.

The host's network configuration:

# Host /etc/network/interfaces
auto lxcbr0
iface lxcbr0 inet static
    bridge_ports p4p1
    bridge_stp off
    bridge_fd 0
    bridge_maxwait 0
    address 192.168.0.200
        netmask 255.255.255.0
        gateway 192.168.0.1
        dns-nameservers 192.168.0.1

The guest's configuration inside the host:

lxc.network.type = veth
lxc.network.flags = up
lxc.network.link = lxcbr0
lxc.network.hwaddr = 00:16:3e:08:b6:78
lxc.network.ipv4 = 192.168.0.201/24

The guest's network configuration:

auto eth0
iface eth0 inet dhcp

When I start the container and use lxc-ls -f I get:

NAME  STATE    IPV4                          IPV6                                    AUTOSTART  
----------------------------------------------------------------------------------------------
name  RUNNING  192.168.0.110, 192.168.0.201  2607:fa48:6de9:f3a0:216:3eff:fe08:b678  YES    

Answer 1

The reason is that you explicitly asked for two IP addresses.

First, you asked the host to configure a static IP address for the container, which is active as the container starts. Then you asked the container to request a second IP address with DHCP.

You should remove those two lines from /etc/network/interfaces if you don't want the second IP address.

Answer 2

if you have a DHCP sever on that network, you will get two IP address, one from the lxc's dhcp server and the second one from your network DHCP